It has long been known (1) that impurities which are suspended as particles in the water can be removed by mechanical filtration unless they are of such small size as to pass through the filtering material and (2) that ultraviolet rays can be utilized to sterilize water. Apparatus used initially to apply this knowledge to the purification of water was cumbersome, expensive and inefficient.
More recently Ultra Dynamics Corporation has offered an ultraviolet water purifier to the public comprising a head removably secured to a housing which contains a filter of annular cross section and an ultraviolet lamp within the central passage in the filter having its one end on which the lamp harness is located passing through the head. The lamp harness makes connection to a conductor from a power box mounted at the side of and adjacent to the head. While it is intended to purify and sterilize water, it is inefficient, difficult to assemble and service, and not satisfactory.